Live panning in audio editing?

Hey everyone.

I do audio editing for my job and my podcast, Endless Reverberations. I primarily work in Amadeus Pro, which I consider myself pretty proficient with. however, there is one effect that I can't seem to manage with any app or plugin. I want to be able to have audio panning through the stereo channels in real time. In other words, its great that I can use Amadeus Pro's built in balance effect to pan a track a specific amount, but I want to be able to have the same control over the panning that one would have with a console, while mastering. I want to be able to make a thirty second clip start out on the far left channel, and slowly pan to the left throughout the thirty seconds. Does anyone know of a plugin or an app on the mac that offers this amount of control? I hope I am making what I am looking for clear, if not let me know.